Inserter systems are typically used by organizations such as banks, insurance companies and utility companies for producing a large volume of specific mailings where the contents of each mail item are directed to a particular addressee. In many respects, a typical inserter system resembles a manufacturing assembly line. Sheets and other raw materials (e.g., enclosures and envelopes) enter the inserter system as inputs. Then, a plurality of different modules or workstations in the inserter system work cooperatively to process sheets until a finished mail piece is produced.
Typically, inserter systems prepare mail pieces by gathering collations of documents on a conveyer. The collations are then transported on the conveyer to an insertion station where they are automatically stuffed into envelopes. After being stuffed with the collations, the envelopes are removed from the insertion station for further processing, such as automated closing and sealing of the envelopes, weighing of the envelopes, applying postage to the envelopes, and finally sorting and stacking the envelopes.
At the input end of a typical inserter system, rolls or stacks of continuous printed documents, called a web, are fed into the inserter system by a web feeder. As will be appreciated, the continuous web must be separated into individual documents pages. This separation is typically carried out by a web cutter that uses a blade forming a part of guillotine cutting module to cut the continuous web into individual document pages.
In one type of web cutter, called a pinned web cutter, the web is provided with sprocket holes on both sides thereof and is fed from a fanfold stack or a roll into the web cutter. The web cutter has a tractor with pins or a pair of moving belts with sprockets to move the web toward the guillotine cutting module for cutting the web cross-wise into separate sheets. Perforations are provided on each side of the web so that the sprocket hole sections of the web can be removed from the sheets prior to moving the cut sheets to other components of the inserter system.
In an alternative type of web cutter, the continuous web is moved by a pair of control nips. Such a system is referred to as a pinless cutter as the continuous web of material does not need to be provided with the sprocket holes described above.
Cut sheet length accuracy and repeatability are critical characteristics for a high speed web cutter. These characteristics are directly correlated to the accuracy and repeatability of an output shaft of a servo motor that controls the motion of a paper web handling device. For a pinned cutter, the paper web handling device is typically a set of tractors and for a pinless cutter, the paper web handling device is typically one or more control nips. For both types of cutters, the web advances beneath a guillotine cutting module having a blade that is located above the web. When the web has advanced almost one cut sheet length, the blade begins a downward motion towards the web. Once the web has come to rest, the blade strikes the paper making a cut. Such feed and cut cycles are carried out in an alternate fashion during the operation of the paper handling device.
It has been found that the accuracy and repeatability of cut sheets varies during operation of web cutters for several reasons, which are described in more detail elsewhere herein.